PROJECT SUMMARY Vascular cognitive impairment and dementia (VCID) is any level of cognitive alteration that is attributable to cerebrovascular pathologies. VCID is second only to Alzheimer's disease as a cause of dementia and accounts for ~15-30% of all dementia cases. Cerebral small vessel diseases (cSVDs) are group of pathologies afflicting the microcirculation of the brain that collectively account for up to 20% of all strokes and is the most common pathology underlying VCID. The impact of cSVD and VCID is expected to increase rapidly as the population of the US and other countries ages. Importantly, the pathogeneses of cSVDs are incompletely understood which represents a major barrier in developing strategies for prevention and treatment. Research described in this proposal will develop and validate five novel mouse models of cSVD based on genes and mutations that are demonstrated to contribute to human disease. We have assembled an interdisciplinary team of experts that will integrate unique genetic resources, vascular pressure myography, patch-clamp electrophysiology, calcium imaging, specialized magnetic resonance imaging modalities and learning and memory behavior assays to develop and characterize multiple novel genetic models of cSVD using genes that contribute to disease in humans. Our long-term objective is to develop and employ genetic models that faithfully recapitulate important hallmarks of human cSVD and VCID.